Tucked away in the high reaches of the Andes mountains, along the border between Bolivia and Peru, lies one of the highest regions inhabited by people anywhere in the world. Here in the “altiplano” farmers raise sheep, llamas and alpacas, as they have for thousands of years. But unlike most farmlands, the altiplano is surrounded by jagged mountains, volcanic peaks that drop steeply down to deserts in some places, to rain forests in others, and on the western side, to a deep trench of the Pacific Ocean.

The Andes are the longest mountain range in the world, stretching 7,250 kilometers (4,200 miles) down the southern half of the world. The Andes run north to the warm equator, and stretch south towards Cape Horn and Patagonia, a windy, cold, semi-desert where the winter temperatures stay below freezing. The southern tip of the Andes is not far from Antartica, home of the south pole!

The name “Andes” comes from a native word whose meaning is unkown today. The tallest peak is Mt. Aconcagua, a giant volcano towering 6,959 meters (22,831 feet) above sea level. The Andes mountains have been formed by one of the crustal plates of the Pacific ocean floor pushing slowly against the American continental plate. This pressure has caused the sedimentary rocks to bend and fold up into long ridges, called “sierras.” Where the sedimentary rocks cracked, molten granite and igneous rocks erupted from below as volcanoes, caused by the oceanic plate melting from the friction and exploding to the surface.

Most of the highest mountains in the Andes are volcanoes, some still active, many dormant or extinct. Eruptions and strong earthquakes can cause landslides on the steep slopes. Rich minerals formed here include gold, silver, tin, copper, platinum, lead, and zinc.

From Lake Titicaca, the highest lake in the world, to Machu Picchu, the most famous Inca ruin in South America, the Andes Mountains are a precious treasure that we all should plan to visit in our lives.